Not Alone follows Katie and her son, Harry, who have survived alone in their haven of a flat for the last five years. Katie is a character with a quiet strength; a woman who has had to rely on herself to survive and care for her young son, alone in a world that has been ravaged by a toxic storm brought on by the climate crisis and microplastics pollution. As she forages for what is safe to eat, Harry remains in the flat, quiet and safe from the dangers of outside: pervasive layers of toxic dust on the ground from the storm and subsequent rains, plastic smog, hungry animals and fear of not being as alone and safe as Katie hopes they are. Life is a relentless cycle of fear, hunger and a longing for the man Katie was meant to marry: Jack, who left for work on the day of the storm and is since presumed dead. However, Katie thinks she might be dying. The cough that has come every winter since the storm has arrived early, and with it, a new pain in her heart. She knows that Harry needs someone other than her to love and protect him. When the peace that they have lived in is shattered by the arrival of another survivor, Katie discovers that the man she loved might still be out there. She takes Harry outside and into the changed and toxic – yet beautiful – world for the first time and on a desperate journey across the country to try to find him.